# `walibc`: A libc for "bare metal wasm" targets.

> [!NOTE]
>
> `walibc` is currently incomplete, not yet usable, and not accepting outside contributions (for the time being).

The goal of this library is to allow Rust code that targets `wasm32-unknown-unknown` (for example) to be able to use Rust crates that bundle C libraries. These targets are effectively bare-metal, and don't come with their own C library, even things like `memcpy` are unavailable (because `string.h` doesn't exist). Unfortunately, they're also widely used, as they don't require installing a separate SDK (such as the WASI SDK, or the Emscripten SDK). `walibc` exists to fill that gap.

This wouldn't be seamless (the C library bundler would have to add a build dep on `walibc`), but it would allow things like (for example) libsqlite3-sys to avoid the need to carry it's own implementation of libc functions.

Currently, it's essentially a header-only subset-of-libc. There aren't an abundance of good reasons for this, but the basic one is it lets us avoid linker issues if two distinct copies of `walibc` are used in a single build with no coordination. A better solution here is leverage cargo to solve this problem for ourselves. That said, this way we avoid colliding with functions provided by compiler_builtins...

That said, making most functions inline goes part of the way towards addressing how naïve many of our function implementations are.

## Non-goals
- Supporting non-Clang compilers.
- Supporting non-wasm targets.
- Supporting non-Rust use, for now.

## License
Public domain, as explained by [the Unlicense](./UNLICENSE). Failing that, the typical Rusty combo of [Apache-2.0](./LICENSE-APACHE) or [MIT](./LICENSE-MIT) is available.

Additionally:
- Portions of `walibc` were ported from [pdclib](https://github.com/DevSolar/pdclib), which is also public domain.
- The implementation of the `vsnprintf`-family of functions is taken from [`stb_sprintf`](https://github.com/nothings/stb/blob/013ac3beddff3dbffafd5177e7972067cd2b5083/stb_sprintf.h) (with some modifications). This is also public domain.